1. Field of the Invention
The present invention relates to a display device having a touch panel function and displaying as a list items specified by operation of this function. The present invention also relates to an image forming apparatus and an electronic device loaded with this display device.
2. Description of Related Art
A recently wide-spread image forming apparatus is of a type, so-called a multifunction printer, having functions as a copier, a printer, a facsimile, and a scanner in combination. Such an image forming apparatus is provided with not only an image formation function but also a communication function of transmitting image data to a distant place via a telephone line or a network line.
The image data communication function is provided with a so-called address book for destination management. The address book is a list of a plurality of destinations arrayed as items. The communication function, based on destination information of a destination specified through search on the address book by the user, sets an address and transmits the image data. Typically, in the image forming apparatus, a display device having the touch panel function is provided on a front surface of the image forming apparatus, and the address book is displayed on this display device.
JP-A-No2008-124751 shows one example of a display device that displays an address book. The display device (touch screen) of a scanner described in this patent document is provided with a destination specification screen, on which an address list display region, up and down buttons of this list, etc. are arranged. On the address list display region, five pieces of address information can be displayed, and displaying other addresses requires moving the list vertically with the up and down buttons. The same operation is required for other electronic devices, such as a cellular phone unit and a PDA, that are provided with an address book.
Since the display device of the scanner described in the patent document above uses the up and down buttons to change the display of the address list, address search is very difficult. In recent years, memory capacity has increased due to technical development, and thus it is not rare to see an apparatus capable of storing, for example, more than 1000 pieces of destination information. Therefore, the display device of the scanner described in the patent document above has poor operability related to the address search, and the search may be further prolonged, resulting in a risk that a sense of discomfort is given to the user.
To improve efficiency in the address search, it is possible to provide input keys that limit addresses to be displayed on the screen. The introduction of the input keys that limit the addresses to be displayed permits shortening of time required for displaying a desired address, resulting in improvement in the operability of the display device related to the address search. However, for the user to perform the address search without taking unnecessary procedures as a result of, for example, a key operation error made by the user, not only simply arraying on the screen the input keys that limit the addresses to be displayed but also elaborating a shape, a size, indication, etc. of the input keys is effective. As a result, the operability of the display device related to the address search further improves.